Every other Friday, the Outside/In team answers a listener question about the natural world. This week's question comes from Lera on Nantucket Island in Mass.
Are there any examples of same-sex animal relationships or same-sex animals raising their young?
Producer Marina Henke looked into it.
Transcript
This has been lightly edited for clarity.
Marina Henke: Listen. I am a hopeless romantic. Put a rom-com in front of me and at some point I will quite earnestly begin to weep. “Love Actually?”
CLIP: That will be… nice!
Marina Henke: “Notting Hill?”
CLIP: I’m also just a girl, standing in front of a boy, asking him to love her!
Marina Henke: I mean c’mon! But when asked to look into pair bonding among animals, I had to face some hard facts. How animals choose to mate can be pretty practical. For the most part, animals mate to reproduce. And they want to do that as easily and successfully as possible. Which, look, as someone who wants kids one day, I get. So how animals do this comes down to all kinds of factors: their reproductive window, their population density, and their environment. Like, when temperatures get hotter, you’re more likely to see multi-queen ant colonies. Or during years of harsher weather, some rodents will band together to raise their young in groups.
Marina Henke: But then there’s the species who just want one partner. Take the albatross, a bird that mates for life. For them, harsher climates lead to something that’s incredibly human sounding: increased divorce rates.
Francesco Ventura: When you think about changes in environmental conditions you don't immediately think about divorce being a consequence.
Marina Henke: That’s Francesco Ventura, a biologist at the Woods Hole Oceanographic Institution who studies albatrosses. Unlike the more common effects of climate change seen in animals – lower birth rates, habitat migration, bad health outcomes – Francesco found that following warmer years, these massive birds were sometimes getting divorced at almost twice the normal rate! His first hypothesis for these broken marriages was pretty straightforward.
Francesco Ventura: When the conditions are tough, birds may return later to the breeding colony or in poorer physiological condition.
Marina Henke: If that happens, breeding between these love birds may not be successful. Which is a big-time trigger for divorce. But after analyzing the data, Francesco has another theory. It’s called the “partner-blaming hypothesis.” Here’s how it works…
Francesco Ventura: In harsh seasons, birds get stressed...
Marina Henke: And turns out female albatrosses do not like stress. So…
Francesco Ventura: It may be possible that harsher conditions trigger higher levels of circulating stress hormones which may be kind of misinterpreted or misread by the female as a poor performance by the mate.
Marina Henke: Did you catch the logic mistake there? Even if a pair of albatrosses successfully breed the year before, if that male shows up to mate stressed out, well… cue the proverbial divorce papers. Now before you start worrying about an albatross loneliness epidemic, Francesco explained to me he does not lose sleep over this.
Francesco Ventura: So I just got back from a breeding colony with over 200,000 breeding pairs. So in this sense it's not an immediate concern for conservation
Marina Henke: But for other monogamous animals with smaller breeding selection and range, a spike in divorces could make for less reproduction overall. Either way, scientists like Francesco think it’s important to look at these ripple effects of climate change, even if it’s a bit less flashy.
Francesco Ventura: When you think about rough environmental conditions, you think about extreme events that wash out the nest and kill hundreds of adult individuals. Yes, that can happen. But also it can tweak and it can modulate the breeding processes that regulates the life of these ocean voyagers.
Marina Henke: Turns out us humans and birds aren’t always that different. Which begs the question, could some bachelor albatrosses use a few rom-coms to distract themselves this weekend?
If you’d like to submit a question to the Outside/In team, you can record it as a voice memo on your smartphone and send it to outsidein@nhpr.org. You can also leave a message on our hotline, 1-844-GO-OTTER.
